Sunset spread her fingers apart from each other as much as she could. The ten long, slender appendages were still weird to manipulate, even three months after coming to the human world. She could now do most things with them without looking clumsy, but actions that required finesse were still a massive work in progress. Her writing was wobbly and hideous, and she still dropped the cutlery one out of ten times. The logical part of her brain told her it was normal to struggle with brand new appendages. The prideful part screamed that she should have already mastered them by now.

“We’re here,” Luna said, snapping Sunset out of her thoughts. “I’ll come back for you on Sunday at noon. Is that alright to you?”

“Yeah,” Sunset replied as she got out of the car.

Twilight had invited Sunset to have a two-night sleepover, starting Friday, with the excuse to keep studying her lesson plan. Sunset didn’t mind the excuse. She herself needed a few days away from the sisters’ apartment. The two women were quiet most of the time, but they could also start arguing at the drop of a hat, and once they got started, they could keep at it for hours. And since the apartment’s walls were rather thin, they made it impossible for Sunset to focus on her studies.

She hoped that Twilight’s house would offer a better studying environment.

Twilight’s mother led her in, waving at Luna from the door. “Twilight’s in her room,” she said. “I’ll call you girls when it’s time for dinner.”

Sunset hefted her backpack and made a beeline to Twilight’s room. She was surprised to find a fully dressed mattress right next to Twilight’s bed.

“Hey, Sunset!” Twilight said from her desk.

Sunset let her backpack fall to the floor next to the door and stepped towards the desk. Apparently, Twilight had been going over some equations. “What are you doing?”

“Just passing the time,” Twilight replied as she closed her notebook. “So, I’ve been thinking, and I have reason to believe that what we feel from the portal is not vibrations.”

Raising an eyebrow, Sunset sat on Twilight’s bed. “I’m pretty sure I know what they are, Twilight. I’ve been studying magic since before I got my Cutie Mark.”

“Just hear me out,” Twilight insisted as she picked another notebook from the small stack on her desk and offered it to Sunset. “While it’s true that the energy feels like vibrations, the way you then describe it as pulsations makes me think otherwise.”

After those first days of studying the portal, the next three full moon nights had happened in the middle of the week, and so they’d only been able to go after class and only for a couple hours. While Twilight was still stuck in just feeling vibrations, Sunset had managed to finally start picking out the different pulsations that made up the enchantments. Twilight’s initial ease in feeling the magic had been surprising, but she was now falling behind in her progress. Of course, the decisive factor there was the difference in their respective experience levels.

“You see, a vibration is the propagation of elastic waves that produces tensions and deformations in an equilibrium point,” Twilight explained. “Whilst pulses, in the way you talk about them, are rapid changes in the amplitude of a signal from a baseline value.”

Sunset opened her mouth to retort, but closed it as she considered Twilight’s words. She’d never looked at it that way. Then again, Equestrian knowledge about the way of the physical world was sorely lacking in comparison to the human world. It was possible that ponies had been using such different concepts interchangeably for lack of better definitions.

“Alright, I’ll bite,” Sunset said. “What else have you got?”

“Since we can only practice feeling the magical energy of the portal every month, it’s going to take me a long while before I can corroborate this myself,” Twilight said. “So, I need you to explain to me how these pulsations become magic spells.”

Sunset opened the notebook Twilight had given her and found it completely blank. A single pencil sat next to the metallic spiral. She snorted and began making some notes.

“There are two major ways in which the Harmonic Veil interacts with the world,” Sunset said as she wrote with uncertain fingers. “The first way is called Macroscale Influence, and it deals with phenomena that are easy to perceive. The Harmonic Resonance is one of these phenomena.

“The second category is called Microscale Influence.” Sunset continued. “This is almost exclusively a unicorn-only field of study, as we are practically the only ones that can affect and detect the Harmonic Veil in such a way.” She took a mouthful of air as she considered how to explain a concept to someone that didn’t have the right appendage to understand. “Basically, the Harmonic Veil can be punctured in fixed points in space, which will create a pulse. If many pulses are combined in a specific order, you get arrays that perform a simple action. Put together many arrays and you’ll get a spell.”

Sunset smiled, feeling quite pleased with herself. She had managed to dumb down the basics of spellcraft circuitry.

Twilight finished writing her own notes, then looked up at Sunset. “That sounds a lot like binary code.”

“Like what?”

It only took Twilight ten minutes to give Sunset a quick explanation of what binary coding was and gave her a few examples. To say that Sunset was surprised would be an understatement.

“Of course, there are some differences,” Twilight said. “There’s no computing machine or compiling software, for one, but it seems that this Harmonic Veil does that on its own.”

Sunset had no idea what a software was, but nodded anyway. “Although that’s the explanation of how spells work in the Microscale Influence. In practice, the pulse arrays can be performed by what we call Spellcraft Circuitry. Unicorn horns, you see, allow us to memorize the patterns of the pulse arrays, then conjure them to put them together with other arrays in the correct sequence that will eventually produce an effect. We call that spellcasting.”

“Can you give me a simple example?” Twilight requested.

“Sure,” Sunset tapped the pencil on her notebook for a moment. “Light producing spells are usually the first unicorns cast by instinct alone, but when you get down to studying them, they are reduced to the following pulse arrays: light production, intensity, duration, manipulation, stability, consumption, and dissipation.”

Twilight nodded and spoke while still writing. “All of that is processed in the Harmonic Veil?”

“Yes. Though the amount of mana required to create such a spell comes from the unicorn’s mana pool. It's possible to use other sources of magical energy to power spells, but that's within the realm of Enchanting.”

“So the difference between Spellcasting and Enchanting is the source of the magical energy?”

“In a nutshell.” Though it was a lot more nuanced than that, but Sunset didn’t want to go over that tangent at the moment.

“And of course you can describe a light producing spell in both the Macro and Microscale Influences,” Twilight muttered. “Fascinating.”

Sunset let herself smile at how easy it was for Twilight to understand Harmonic Theory. Back when she was a student at Celestia’s school, Sunset had always found baffling how unicorns struggled to understand these concepts even after they’d been simplified. So the fact that Twilight, who didn’t have a magical upbringing, understood this easily only reaffirmed Sunset’s confidence in her superiority over all those other unicorns.

Twilight picked some books from her shelves and opened them on the bed around Sunset. “If the Harmonic Veil works the same in this world as it does in yours, then we should be able to build a machine that detects the pulsations and translates them into a visual representation.”

“Yeah…” Sunset said as she picked one of the books, barely managing to recognize what the symbols were meant to represent. She pursed her lips as she mulled over the speed at which Twilight had been absorbing every little bit of knowledge Sunset had given her about magic. It was as if her previous understanding of human technology was accelerating her understanding of magic, instead of the other way around.

Sunset felt a sense of unease as she kept reading the books Twilight was giving her. Each more complex than the last. How was it that a society that refused to believe in magic had developed technological concepts that were so similar in practice to magic?

She gasped quietly as an idea popped in her head. Was this the secret to this world? Was understanding human technology what Sunset was supposed to do in order to learn why it was connected to Equestria? Or was it perhaps that Sunset was meant to help humans understand and harness magic, then go back to Equestria and bring them technology? Was the way to becoming an alicorn reaching a balance between both worlds?

But of course! What other reason could there be?

With restored confidence and a grin on her face, Sunset grabbed her pencil with a hand and a book with the other and followed Twilight’s lead into learning more and more advanced concepts. And the more she learned about binary code and computer programming, the more she could see the similarities between the two.

A knock to the door broke the girls’ concentration. How long had they been studying? A glance at the wall clock told Sunset it had been about three hours.

“Come in!” Twilight called a few seconds after the knock. When the door opened, however, Twilight became a blur, moving so fast Sunset almost wondered if the girl had been a pegasus all this time. “Cadence!” Twilight cried out as she tackled an older woman.

Sunset flinched at the name as her eyes properly settled upon the newcomer. The woman’s skin was pink, her eyes violet, and her long hair was partitioned in three very distinct sections of purple, pink, and yellow. All of those were colors that Sunset could perfectly relate to the one name Twilight had called. Not only that, but a look at the woman’s neck showed a thin gold chain that held a die cut piece of metal in the shape of a blue crystalline heart.

Mi Amore Cadenza’s Cutie Mark.

Sunset brought a hand to her mouth and looked down. The thought had crossed her mind upon learning Celestia’s name and seeing the Sun Princess’ Cutie Mark around the Principal’s belongings, but it had long been archived in Sunset’s memory as a single freaky coincidence. However, with yet another freaky coincidence right in front of her, Sunset had to seriously consider the possibility that the mirror aspect of the portal extended further and that… The whole human world was somehow mirroring Equestria.

Of course, that alone raised many other questions. Especially around Celestia herself. One was an immortal alicorn who had lived for well over a thousand years, while the other was a regular human whose district ID said was only thirty-nine. If that was true, then it meant this world couldn’t possibly be an exact mirror. It meant that there was yet another secret to unravel, another conundrum to solve, before Sunset could ascend into an alicorn herself.

“Sunset?” Twilight asked, and her face was only a few centimeters away. “Are you ok?”

Sunset blinked. “Yeah…” Had she really zoned out so much she had completely ignored everything else? She couldn’t afford being so careless. “I was just thinking about… something.”

Twilight gave her a slow nod, then smiled and straightened up. “Well, I just wanted to introduce you to Cadence!” She said, stepping away so that Sunset had an unobstructed view of the woman, who was still standing at the door. “She used to be my babysitter, and then started dating my brother!”

Cadence giggled, and the sound brought flashbacks to a certain pink alicorn. “It’s nice to finally meet you, Sunset. Twilight’s told me a lot about you.”

Sunset turned her head to Twilight and lifted an eyebrow. “A lot, huh?”

“That’s right!” Cadence said chirpily. “How you girls like to study together. Honestly, I’m really glad Twilight found a friend that shares her interests. Anyway, I came here to tell you that dinner’s ready.”

“Okay!” Twilight said. “We’ll be down in a minute.” When Cadence left, closing the door behind her, Twilight spun her head towards Sunset and crossed her arms, giving her the smuggest grin Sunset had seen on the girl. “You really thought I told her the truth about you, didn’t you? I’ll have you know I take my promises very seriously.”

“Yeah, ok, fine,” Sunset said. “Let’s go have dinner.” Not that Sunset felt especially hungry, but she wanted to see if this Cadence shared any more similarities to her pony counterpart. Granted, Sunset hadn’t really known Cadence that well, choosing to avoid the alicorn that so shamelessly claimed the title of princess without knowing the first thing about politics or economy or even the basics of magic.

As it turned out, human Cadence was every bit as annoying as the pony one. Laughing at every stupid joke she heard, softly touching the people around them on their shoulder to remind them that she was still there, always joining in the conversation despite not being invited, and asking questions to know about things she ignored.

Her only saving grace was the fact that she wasn’t an alicorn princess. As long as she was kept in the dark about Equestria, Sunset didn’t need to be on the lookout. She had enough with Celestia breathing down her neck about every little thing she did.

“So,” Cadence said as soon as the previous conversation finished. “What are you girls studying?”

Sunset narrowed her eyes, but before she could tell her to beat it, Twilight replied. “Computer programming.”

“What brought this on? I thought you were studying, uh…”

“The properties and effects of vibrations through different mediums,” Twilight said happily. “But we already dropped that in lieu of recent discoveries. However, I can’t say any more. Our research is top secret.”

“I don’t see why you can’t tell Cadence, Twilight,” Twilight’s mom said. “You already told Shining, after all.”

Cadence turned a smiling face to Shining. “Is that so?”

Shining didn’t seem surprised or even taken aback. He simply kept his expression neutral as he matched Cadence’s gaze. “Sorry, Cady. Sibling code, section two, article third. It's very clear on sibling-shared secrets.”

Cadence pursed her lips and harrumphed, though the smile didn’t quite leave her face. “Well, I suppose I can accept that.”

Sunset didn’t dare look at Twilight, knowing that the girl was most likely being a smug brat about her brother being perfectly capable of keeping a secret.

But just as the conversation was finally going to steer away from topics Sunset would rather avoid, her fingers shook and she dropped the fork half-way to her mouth, making a loud clunk as it hit her plate. She frowned at the offending appendages. She had thought she had already moved on from dropping cutlery.

“Are you alright, Sunset?” The question was asked by at least three different people.

“Yeah, I’m just…” She bit her lip. If she said she wasn’t used to having fingers, she’d have to explain why.

“She’s a bit clumsy with her hands,” Twilight offered.

Sunset blinked, thankful for the save. “That’s right. Can’t get these darned things to work properly.” She added a little demonstration by wiggling her fingers.

Unfortunately, the next one to speak was the pink menace. “If you want to improve your finger dexterity, might I suggest learning a musical instrument?”

A musical instrument? Sunset had only seen some of those when visiting the theater, though the royal guards were trained to play trumpets and drums. They were made to be used with hooves, wings, or magic, but then again, she supposed humans would have adapted them to be operated with hands and fingers. In any case, she thought of refusing the suggestion simply because it had been Cadence who had proposed it.

“That’s a wonderful idea!” Twilight exclaimed, joining her palms together in a quiet clap. “You could play the violin.”

“Violin?” Sunset asked. She had a vague idea of what a violin was. If her memory served her right, it was an instrument oftentimes used in high-class plays and during noble soirées. Refined was the word used for such things. Appropriate for a soon-to-be princess such as Sunset herself.

She hummed, then looked at Twilight. “There’s no harm in at least trying.”

Author's Note

This chapter has been full of technobabble. I hope it was easy to understand the general idea I'm going for. Later chapters will build upon this one's concepts and expand on them.

A wild Cadence has appeared! Sunset used stinky eye. It's not very effective.

I hope you liked it!